import pygame
import random
from random import randint

pygame.init()

WHITE = 255, 255, 255
BLACK = 0, 0, 0,

def GenerateColor():

    return randint(0, 255), randint(0, 255), randint(0, 255)

def GenerateSpeed():

    return random.uniform(0.8, 1.2)

def GenerateSize():

    return randint(10, 20)

def MutateColor(color):

    old_red, old_green, old_blue = color[0], color[1], color[2]
    change_red, change_blue, change_green = randint(-5, 5), randint(-5, 5), randint(-5, 5)

    new_red = old_red + change_red
    if new_red > 255:
        new_red -= abs(change_red)
    elif new_red < 0:
        new_red += abs(change_red)

    new_green = old_green + change_green
    if new_green > 255:
        new_green -= abs(change_green)
    elif new_green < 0:
        new_green += abs(change_green)

    new_blue = old_blue + change_blue
    if new_blue > 255:
        new_blue -= abs(change_blue)
    elif new_blue < 0:
        new_blue += abs(change_blue)

    return new_red, new_green, new_blue

def MutateSpeed(speed):

    return random.uniform(0.8, 1.6) * speed


class Cell(pygame.sprite.Sprite):

    def __init__(self, color, speed, size):
        super().__init__()
        self.color = color
        self.speed = speed
        self.size = size

        self.image = pygame.Surface([size * 4, size * 4])
        self.image.fill(WHITE)
        self.image.set_colorkey(WHITE)

        self.rect = self.image.get_rect()
        pygame.draw.circle(self.image, color, [size, size], size)


w_size = 700, 500
screen = pygame.display.set_mode(w_size)
pygame.display.set_caption('Evolution')

done = False
clock = pygame.time.Clock()

cell_list = pygame.sprite.Group()

for i in range(25):

    cell = Cell(GenerateColor(), GenerateSpeed(), GenerateSize())
    cell.rect.x = randint(0, w_size[0] - 100)
    cell.rect.y = randint(0, w_size[1] - 100)
    cell_list.add(cell)

while not done:

    for event in pygame.event.get():
        if event.type == pygame.QUIT:
            done = True

    screen.fill(WHITE)

    for cell in cell_list:

        direction = randint(0, 3)

        if direction == 0:
            cell.rect.x += cell.speed
        elif direction == 1:
            cell.rect.x -= cell.speed
        elif direction == 2:
            cell.rect.y += cell.speed
        elif direction == 3:
            cell.rect.y -= cell.speed

    cell_list.draw(screen)
    pygame.display.flip()
    clock.tick(60)